package com.example.takeaways.filter;

import com.alibaba.fastjson.JSON;
import com.example.takeaways.common.BaseContext;
import com.example.takeaways.common.R;
import com.example.takeaways.entity.User;
import com.example.takeaways.service.UserService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经完成登录
 */
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Autowired
    private UserService userService;  // 注入 UserService 用来查询用户

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1、获取本次请求的URI
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}", requestURI);

        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login"
        };

        //2、判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        //3、如果不需要处理，则直接放行
        if (check) {
            log.info("本次请求{}不需要处理", requestURI);
            filterChain.doFilter(request, response);
            return;
        }

        //4-1、判断是否是 employee 登录
        Object employeeSession = request.getSession().getAttribute("employee");
        if (employeeSession != null) {
            log.info("员工已登录，员工id为：{}", employeeSession);

            Long empId = (Long) employeeSession; // 获取 employee 的 ID
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request, response);
            return;
        }

        //4-2、判断是否是 user 登录
        Object userSession = request.getSession().getAttribute("user");
        if (userSession != null) {
            log.info("用户已登录，用户id为：{}", userSession);

            // 判断 session 中存储的是否为 User 对象
            if (userSession instanceof User) {
                User user = (User) userSession;  // 强制转换为 User 对象
                Long userId = user.getId();  // 获取 User 对象的 id 属性

                // 通过 ID 查询 User 对象
                if (user != null) {
                    BaseContext.setCurrentId(userId);
                    filterChain.doFilter(request, response);
                    return;
                }
            } else if (userSession instanceof Long) {
                Long userId = (Long) userSession;  // 如果 session 中存储的是 User ID
                BaseContext.setCurrentId(userId);
                filterChain.doFilter(request, response);
                return;
            }
        }

        log.info("用户未登录");
        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
